Diagnostic Services Audiologists perform measurements of the entire auditory system from the ear canal to the cortex (brain) to provide a comprehensive assessment of a patent's auditory or balance system. In this manner the appropriate diagnosis and treatment plan can be initiated in order to resolve a patient's concerns. The following procedures are included in the audiologists scope of practice; * Complete Diagnostic Audiology - Evaluates the status of the auditory system, revealing the degree and type of hearing loss. This procedure is the introductory test that guides the audiologist in determining the need for other protocols. It also provides information as to whether or not a patient has a medical problem causing the loss of hearing or if the person has a non-medical etiology. This procedure requires a one hour time period which allows for counseling and discussion of the findings. * Acoustic Impedance Measurements - Determines the mobility of the eardrum and associated middle ear bones. Many children develop fluid behind the eardrum due to upper respiratory infections. This procedure can make a direct measurement of the middle ear system to rule out the possiblity of a middle ear problem. Other disorders are also assocated with middle ear dysfunction. This procedure requires a five minute period. * Auditory Brainstem Response (ABR) - Measures the integrity of the neurologic system leading from the inner ear (cochlea) to the central auditory mechanism. This procedure is used to assist in ruling out a lesion affecting the central auditory nervous system. It is also used in determining the hearing levels of children. This procedure requires a one hour period. * Otoacoustic Emissions (OAE) - Measures the performance of the outer hair cells of the inner ear. This procedure is extremely useful when evaluating the hearing of young children. Pitch specific information can be obtained in a very short period of time. The first clinical application of Otoacoustic Emissions began in the United States only within the past several years. This procedure requires an actual test time of 5-30 seconds per ear. * Electronystagmography (ENG) - Determines the status of the vestibular (balance) system. This procedure is the primary method of documenting a patient's dizziness. Ten percent of complaints to an internal medicine doctor relates to a concern about dizziness or vertigo. Many patients who have dizziness experience problems when they rotate their heads in different postions. This type of dizziness may be caused by what is termed postional vertigo that can be treated and cured by the audiologist with one or two visits. The ENG procedure requires one hour and 15 minutes. * Electrocochleography (ECOG) - Measures the role of the inner ear for suspected cases of Meniere's disease. This procedure can also track the progress of other disorders that affect the organ of corti. The Ecog procedure requires one hour. * Loudness Mapping - Determines the growth of loudness to various pitches. All patients with a hearing loss due to a problem of the inner ear (most common, 96%) have an abnormal loudness perception. This measurement needs to be taken into account when determining the appropriate type of hearing aid system for a patient. This procedure requires 20 minutes. * Tinnitus Evaluation - Measures the pitch and loudness of ringing in the ears. Many patients with and without hearing loss experience ringing in the ears. This evaluation determines the extent of the subjective sensation and allows the audiologist to recommend a treatment plan. This procedure requires 15 minutes.